La0.6Sr0.4MnO3 particles were prepared using the sol-gel method with an external magnetic field (Hext similar to=similar to 4 similar to kOe) and without an external magnetic field. Structural and magnetic properties were systematically investigated. X-ray powder diffraction results show that both samples are single-phase. The results of field-emission scanning electronic microscopy show that the mean particle size of the sample synthesized under Hext similar to=similar to 4 similar to kOe are slightly larger than that of the sample without an external magnetic field. The enhanced magnetic properties are attributed to the less disordered defects induced by an external magnetic field.